How to use json_decode? - php

Question

I have the following Json file:
[{"Datum":"21-07-2017","Zeit":"21:48","Menge":"545465476"},{"Datum":"21-07-2017","Zeit":"21:51","Menge":"78"},{"Datum":"21-07-2017","Zeit":"21:53","Menge":"456"}]
The Json validator says its ok.
But still I cannot this Json file via php_decode(). Instead I am getting "bool(false)"
My code
$jso = json_encode($jfile);
var_dump(json_decode($jso));
$error = json_last_error();
What am I doing wrong?
This script is saving an input to a txt database in Json format.

Answer 1

Your JSON encode and decode look correct. You can refer to the following resources for confirmation:
http://php.net/manual/en/function.json-decode.php
http://php.net/manual/en/function.json-encode.php
So the problem, most likely, lies in the way you get the json into the functions. In your case this is done with a variable "$jfile".
I suggest you do a var_dump of the $jfile variable to see what data it holds, if any.
My first guess, as others have pointed out as well, is that you're reading the json from a file (hence $jfile). This is usually done with the "file_get_contents" function which is described in detail here.
A working example
Your directory structure should look like this:
.
├── readjson.php
├── some_json_data.json
And your php code should look something like this:
<?php
$jfile = file_get_contents('some_json_data.json');
var_dump($jfile)
$jso = json_encode($jfile);
var_dump($jso);
$decoded_json = json_decode($jso);
var_dump($decoded_json);
$error = json_last_error();
?>
Note how I add more var_dump's and variables to explicitly monitor the state of the json objects. This might be helpful when learning new stuff.

Answer 2

I guess you have to first get the file into php, so $jso will hold json data (in terms of file contents)
$jso = file_get_contents('JSON_FILE_PATH');
//then simply use json_decode
var_dump(json_decode($jso));